System and method for producing foamed and steamed milk for hot beverages

ABSTRACT

A foamed milk system for creating foamed milk from a source of milk, a source of air, and a source of steam. The system may include a milk inlet system for pressurizing the milk, an air inlet system for pressurizing the air, a mixing area to mix the pressurized milk, the pressurized air, and the steam, and an expansion area to expand the mixture of the pressurized milk, the pressurized air, and the steam.

TECHNICAL FIELD

The present invention relates generally to a beverage system and moreparticularly relates to systems and method for producing foamed andsteamed milk for beverages.

BACKGROUND OF THE INVENTION

Hot beverages such as cappuccinos and lattes are becoming increasinglypopular. Commercial businesses from fast food restaurants to coffeehouses are providing these hot beverages to their customers. Althoughhot beverages may be made in sufficient quantity for a high volumerestaurant, many customers may prefer a freshly brewed beverage.Likewise, these customers also may prefer freshly made foamed or steamedmilk in their hot beverage. The foamed or steamed milk generally is ofhigher quality if it is made fresh for each customer. However, currenttechnology may not produce foamed or steamed milk quickly or efficientlyenough to satisfy consumer demands.

Generally described, foamed milk may be produced using steam, milk, andair, whereas steamed milk is produced using only steam and milk.Specifically, steam, milk, and/or air may be forced through a singleventuri orifice. The steam, milk, and/or air may then be mixed as theypass through the single venturi orifice. The milk, steam, and/or air,however, may not be sufficiently mixed. Insufficient mixing mayintroduce inefficiencies that result in some of the milk not beingconverted to foam. Furthermore, it may take a considerable amount oftime to produce the foamed or steamed milk by forcing the steam, milk,and/or air through the single venturi orifice.

What may be desired, therefore, is a foamed or steamed milk dispenserthat can produce foamed and steamed milk in an efficient, high quality,and high speed manner to individual consumers in individual servings.The device, however, preferably should be easy to use, easy to maintain,and be competitive in terms of cost.

SUMMARY OF THE INVENTION

The present invention thus provides a foamed milk system for creatingfoamed milk from a source of milk, a source of air, and a source ofsteam. The system may include a milk inlet system for pressurizing themilk, an air inlet system for pressurizing the air, a mixing area to mixthe pressurized milk, the pressurized air, and the steam, and anexpansion area to expand the mixture of the pressurized milk, thepressurized air, and the steam.

The milk inlet system may include a peristaltic pump. A disposable hosemay connect the peristaltic pump and the source of milk. The air inletsystem may include an air pump. A hose connector may connect the milkinlet system and the air inlet system. The hose connector may include athree-way or a four-way valve. The hose connector may include a numberof barbed connections. The milk inlet system and the air inlet systemmay both include disposable hoses connecting the hose connector. Thedisposable hose for the air inlet system may include a microfilter andone or more check valves. A disposable hose also may connect the hoseconnector and the mixing area. A steam hose may connect the source ofsteam and the mixing area.

The mixing area may include a hollow nozzle block. A mixture nozzle maybe positioned within the hollow nozzle block. The mixture nozzle mayinclude a number of protrusions positioned thereon and a number oforifice area positioned about the protrusions. The mixture nozzle may beremovable.

The foamed milk system further may include a diffuser to gather the flowof the foamed milk to be dispensed. The diffuser may include a diffuserinsert and a spout.

The foamed milk system further may include a sanitation system. Thesanitation system may include a source of hot water. The hot water flowsthrough the mixing area and the expansion area via a sanitation hose.

A further embodiment of the present invention provides for a steamedmilk system for creating steamed milk from pressurized milk and steam.The system may include a mixing area to mix the pressurized milk and thesteam, a pressurized milk inlet system for injecting the pressurizedmilk into the mixing area, a steam inlet system for injecting the steaminto the mixing area, an expansion area to expand the pressurized milkand the steam to form a flow of steamed milk, and a diffuser to gatherthe flow of the steamed milk to be dispensed.

A method of the present invention may provide for a sanitizing adispenser serving foamed milk from a source of pressurized milk and asource of pressurized air. The pressurized milk and the pressurized airmay be fed through a number of hoses and mixed together in a mixingnozzle. The method may include providing a source of hot water,connecting the source of hot water to one or more of the number ofhoses, flowing the hot water through the one or more of the number ofhoses and the mixing nozzle, disconnecting the source of hot water, andrepeating the above steps on a predetermined schedule.

The predetermined schedule may include about every two (2) hours. Thehot water may include about 190 degrees Fahrenheit (about 87.8 degreesCelsius). The method further may include the steps of replacing thenumber of hoses on a second predetermined schedule. The secondpredetermined schedule may include about daily.

A further method of the present invention may provide for producingfoamed milk from milk, air, and steam. The method may includepressurizing the milk and the air, injecting the pressurized milk, thepressurized air, and the steam into a mixing area, and depressurizingthe milk, air, and steam mixture to ambient pressure to create thefoamed milk.

These and other features of the present invention will become apparentupon review of the following detailed description when taken inconjunction with the drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the foamed milk system of the presentinvention.

FIG. 2 is a plan view of the mixing nozzle insert shown with the nozzleblock in cross-section.

FIG. 3 is a perspective view of the nozzle insert and protrusions.

FIG. 4 is a perspective view of an alternative embodiment of a cleaningblock junction.

DETAILED DESCRIPTION OF THE INVENTION

Briefly described, the present invention injects pressurized milk, air,and steam into a mixing area of a nozzle body. The milk, air, and steammay be intimately and thoroughly mixed within one or more orifice areas.The mixture then proceeds to an expansion area where the mixture expandsto ambient pressure. The expansion causes the milk to foam. The foamedmilk may then be collected with a diffuser and dispensed into a cup. Thepresent invention also can be used to produce steamed milk only byintroducing steam and milk to the foamed milk system.

Referring now to the drawings in more detail, in which like numeralsrepresent like elements throughout the several views, FIGS. 1-3 show afoamed milk system 100 of the present invention. The foamed milk system100 may include a pressurized milk inlet system 110. The pressurizedmilk inlet system 110 may provide pressurized milk to the foamed milksystem 100 as a whole. The pressurized milk inlet 110 system may includea milk supply 120, a milk pump 130, and a plurality of milk hoses 140,150. The milk inlet system 110 may be positioned within a refrigeratedcontainer 155. The refrigerated container 110 may be any type ofstandard refrigeration system. The milk supply 120 may include any typeof container, including a carton, a bag in box, or any other type ofstorage device. The milk itself may be UHT (Ultra High Temperature)milk. The milk preferably is maintained at about 40 degrees Fahrenheit(4.4 degrees Celsius) or lower after opening. The milk preferably isreplaced when the milk supply 120 is empty or about every 48 hours orso.

The milk hoses 140, 150 may be made out of rubber, copper, stainlesssteel, other types of metals, plastics, and other types of substantiallynon-corrosive materials. The materials preferably are food grade. Thehoses 140, 150 preferably are disposable. Although any length may beused, the hoses 140, 150 preferably are as short as possible to limitthe length the milk must travel out of the milk supply.

The first milk hose 140 may connect the milk supply 120 to the milk pump130. The milk pump 130 may pressurize and meter the milk. The milk maybe pressurized between about two (2) and about forty (40) pounds persquare inch (psi) (about 0.14 to about 2.8 kilograms per squarecentimeter (ksc)) depending on the flow rate desired. The presentembodiment may pressurize the milk to about fifteen (15) psi (about one(1) ksc). The milk pump 130 may be a peristaltic pump to better meterthe milk. The peristaltic pump also may have the advantage of reducingthe risk of backflow and, hence, reducing the risk of somehowcontaminating the milk. Any other type of pump that pressurizes andmeters the milk is contemplated for use herein.

The foamed milk system 100 also may include a pressurized air inletsystem 160. The pressurized air inlet system 160 may provide pressurizedair to the foamed milk system 100. The air may be pressurized to betweenabout two (2) and about forty (40) psi (about 0.14 to about 2.8 ksc)using an air pump 170 depending on the desired flow rate. The presentembodiment may pressurize the air to about fifteen (15) psi (about one(1) ksc). The air pump 170 may be any pump design that providescompressed air. The pressurized air may be delivered via an air hose180. The air hose 180 may include a microfilter 175 or a similar type ofdevice to remove any impurities in the air stream.

The pressurized milk and the pressurized air may be combined andpre-mixed. The pressurized milk inlet system 110 and the pressurized airinlet system 160 may be joined at a hose connector 185 via the secondmilk hose 150 and the air hose 180. The hose connector 185 may includethree (3) hose fittings 190, 200, 210. Any type of three (3) way valvemay be used. The milk hose 150 may connected the output of the milk pump130 and the first hose fitting 190. The air hose 180 may connect theoutput of the air pump 170 and the second hose fitting 200. Thepressurized air and pressurized milk may be combined into one stream inthe hose connector 185 to allow the mixture to exit through the thirdhose fitting 210.

As described above, the hose connector 185, the milk hose 150, and theair hose 180 may be made out of copper, stainless steel, other types ofmetals, plastics, rubber, and other types of substantially non-corrosivematerials as described above. These elements may be detachable to allowfor easier cleaning. The hose fittings 190, 200, 210 and the otherconnections described herein may be barbed and may include polishedsurfaces to prevent crevice accumulation. The hoses 150, 180 preferablyare disposable. The length of the hoses 150, 180 preferably is as shortas possible.

A mixture hose 220 may connect the hose connector 185 to a mixture inlet230 of a nozzle body 240 to transport the milk and air mixture. Themixture hose 220 may be made out of copper, stainless steel, other typesof metals, plastics, rubber, or other types of substantiallynon-corrosive materials as described above. The hose 220 preferably isdisposable and as short in length as possible. The mixture hose 220 maybe attached to the nozzle body 240 by fitting the mixture hose 220 intothe mixture inlet 230. Alternatively, a clamping mechanism or any othermethod to secure the mixture hose 220 in the mixture inlet 230 known inthe art may be used.

The nozzle body 240 may be a substantially hollow block-like structure.The nozzle body 240 may be made out of stainless steel, aluminum,plastic, or any other substantially non-corrosive material. The nozzlebody 240 may include an inner wall 250 and an outer wall 260. The innerwall 250 may define a mixing area 310 as will be described in moredetail below. The mixing area 310 may be substantially conical in shape.

The mixture inlet 230 may pass through the nozzle body 240 to the mixingarea 310. The mixture inlet 230 may be a hollow region in the nozzlebody between the inner wall 250 and the outer wall 260 that allows themixture hose 220 to fit into the nozzle body 240 and allows the milk andair mixture to pass to the mixing area 310. The mixture inlet 230 alsois contemplated to include an insert or any other means of allowing themixture hose 220 to feed the mixture into the mixing area 310. Themixture inlet 230 may include a barbed connector. The present inventionis not limited to pre-mixing the pressurized air and milk prior to themixing area 310. It is contemplated that the milk and air may enter themixing area 310 jointly or separately.

The foamed milk system 100 also may include a pressurized steam inletsystem 235 that provides steam to the foamed milk system 310. The steaminlet system 235 may include a steam generator 270, a steam hose 280,and a steam inlet 290. The steam generator 270 may be a heat exchanger,a boiler, or any other device that creates pressurized steam. Steam inthe present embodiment may be pressurized to about forty (40) psi (about2.8 ksc) or so. The pressure may be higher or lower depending on therate of foam production required. The steam hose 280 may be used totransport the pressurized steam from the steam generator 270 to thesteam inlet 290. The steam hose 280 may be made out of copper, stainlesssteel, other types of metals, plastics, rubber, or other types ofsubstantially non-corrosive materials as are described above. The steamhose 280 may be attached to the nozzle body 240 by fitting the steamhose 280 into the steam inlet 290 by a clamping mechanism or by anyother method known in the art.

The steam inlet 290 may pass through the nozzle body 240. The steaminlet 290 may be a hollow region in the nozzle body 240 between theinner wall 250 and the outer wall 260 that allows the steam hose 280 tofit into the nozzle body 240 and the steam to pass to the mixing area310. The steam inlet 290 may include a barbed connector. It is alsocontemplated that the pressurized steam may be pre-mixed with thepressurized milk and/or air prior to entering the mixing area 310.

As described above, the inner wall 250 of the nozzle body may define themixing area 310. The inner wall 250 and the mixing area 310 may betapered to allow a nozzle insert 300 to fit therein. The nozzle body 240may be made of stainless steel, aluminum, plastic, or any othersubstantially non-corrosive material. The nozzle insert 300 may betapered in a similar manner as the mixing area 310 so as to allow theinsert 300 to fit inside of the nozzle body 240. The nozzle insert 300may be solid or hollow.

The nozzle insert 300 may be locked into the nozzle body 240 by using atwist lock mechanism, by a screwing mechanism, or by any otherattachment means known in the art. The screwing mechanism, for instance,may include a screw attached to the top end of the nozzle insert 300that screws into a threaded channel in the nozzle body 240.

The insertion of the nozzle insert 300 may create an annular regionbetween the inner wall 250 of the nozzle body 240 and the nozzle insert300. The annular region defines the mixing area 310 for the milk, air,and steam. In the mixing area 310, the milk, air, and steam becomeintimately mixed so as to increase the efficiency of the system. Asdepicted in FIGS. 2 and 3, the nozzle insert 300 also may contain anumber of protrusions 320 to aid in the mixing of the milk, air, andsteam. The protrusions 320 may contact the inner wall 250 of the nozzlebody 240 when the nozzle insert 300 is placed inside the nozzle body240. The spaces between the protrusions 320 may create a number oforifice areas 330. The use of the protrusions 320 in the mixing area 310may promote turbulent fluid flow therein. This turbulent fluid flow mayenhance mixing of the milk, air, and steam passing there through.However, turbulent flow is not required so long as sufficient mixing isachieved.

In an exemplary embodiment of the present invention, the nozzle body 240may be about three (3) inches (about 7.6 centimeters) long andsubstantially cylindrically shaped. The nozzle insert 300 also may besubstantially cylindrically shaped and about one (1) inch (about 2.5centimeters) long and about 0.6 inches (about 1.5 centimeters) indiameter at the base. The inner wall 250 of the nozzle body 240 and thenozzle insert 300 may be tapered at about a 10.5 degree angle. Thenozzle insert 300 may only be tapered for about 0.8 inches (2centimeters) of the length and the remaining length may not be tapered.The exemplary embodiment may include about two (2) rows of protrusions320 with about sixteen (16) protrusions 320 per row within the mixingarea 310. The protrusions 320, in the exemplary embodiment, may be about0.029 inches (about 0.7 millimeters) tall and about 0.06 inches (1.5millimeters) wide. The rows may be about one-third inch (about 0.85centimeters) apart. Any number of protrusions 320, rows of protrusions320, or size of protrusions 320 is contemplated so as to enhance themixing of the milk, air, and steam. Further, the present invention isnot limited to the dimensions in the exemplary embodiment. The nozzlebody 240 and the nozzle insert 300 are contemplated to be any size andtapered at any angle that may create an adequate space for use with thepresent invention.

Adjacent to the mixing area 310 may be an expansion area 340. Theexpansion area 340 may be located where the annular region between theinner wall 250 of the nozzle body and the nozzle insert 300 begins towiden or ends. The expansion area 340 may be at or about ambientpressure. As the pressurized milk, air, and steam mixture reach theexpansion area 340 from the mixing area 310, the mixture may begin toexpand as the pressure of the mixture is reduced to about ambientpressure. This expansion may cause the milk, air, and steam mixture tofoam as the pressure is reduced.

The foam then may be collected using a diffuser 350. The diffuser 350may be used to control and collect the foam from the expansion area 340and dispense the foam into a cup or mug 380. The diffuser 350 mayinclude a diffuser insert 360 and a spout 370. The diffuser insert 360may be cylindrically shaped and may be tapered to funnel the foam to thespout 370. The diffuser 350 may be made of stainless steel, aluminum,plastic, or any other substantially non-corrosive material. Any type ofdiffuser system is contemplated herein that allows the user to collectand dispense the foam into a cup or mug 380.

The diffuser insert 360 and the bottom of the nozzle body 240 may bethreaded so as to allow them to be screwed together. The diffuser insert360 also may snap into the nozzle body 240 or be connected in any othermeans known in the art. The spout 370 may be threaded and screwed intothe bottom of the diffuser insert 360, snapped into the bottom portionof the diffuser insert 360, or connected to the diffuser insert 360 inany other manner known in the art.

The exemplary embodiment may produce about eight (8) ounces (about 236.6milliliters) of foam for an individual serving. The foam may be producedat a rate of about 0.375 ounces/second (about 11 milliliters/second) byproviding pressurized milk at about 0.375 ounces/second (about 11milliliters/second) for about eight (8) seconds, pressurized air atabout fifteen (15) psi (about one (1) ksc) for about eight (8) seconds,and pressurized steam at about fifteen (15) psi (about one (1) ksc) forabout eight (8) seconds into the mixing area 310. The temperature of themilk may be about 155 degrees Fahrenheit (about 68.3 degrees Celsius) orso. The temperature of the nozzle body 240 may reach about 212 degreesFahrenheit (about 100 degrees Celsius). The present invention is in noway limited to the exemplary embodiment and can be of any size,dimension, operating conditions, and flow rates necessary for thedesired foam production.

The foamed milk system 100 also may be used to produce steamed milk forlattes and other hot beverages. The foamed milk system 100 may be usedin substantially the same manner to produce steamed milk as it is usedto produce foamed milk. Steamed milk may be produced by only introducingmilk and steam into the foamed milk system 100. Thus, the pressurizedair inlet system 160 would not be used. Milk from the pressurized milkinlet system 110 and steam from the pressurized steam inlet system 235may be introduced to the mixing area 310, expanded in the expansion area340, collected with the diffuser 350, and dispensed into the mug or cup380 to produce the steamed milk desired. The present embodiment maypressurize the milk to about fifteen (15) psi (about 1 ksc) and thesteam to about forty (40) psi (about 2.8 ksc) to produce steamed milk ata rate of about six (6) ounces per second (about 177.4 milliliters persecond). Any pressure, however, may be used to accommodate a similar ordifferent steamed milk production rate.

The foamed milk system 100 also may include a sanitation system 500. Thesanitation system 500 may include a source of hot water 510. The hotwater supply 510 may be the hot water storage tank of a coffee brewer(not shown) or a similar type of device. The hot water supply 510 may beconnected to the air hose 180 via a hot water hose 520. A sanitationvalve 530 may open and shut the hot water hose 520. The sanitation valve530 may be a solenoid valve or a similar type of device. A T-joint 540or a similar type of device may join the air hose 180 and the hot waterhose 520. One or more check valves 550 may be placed on either side ofthe T-joint 540 to prevent backflow.

In order to flush the milk system 100, the sanitation valve 530 isopened and allows hot water to flow from the hot water source 510through the hot water hose 520 and the check valves 550. The hot wateris delivered to the hose connector 185, the mixture hose 220, and thenozzle body 240. A sufficient quantity of water is delivered to ensurethat all internal services reach a temperature of at least about a 190degrees Fahrenheit (about 87.8 degrees Celsius). This flush cycleensures that all elements outside of the refrigerated container 155 orin connection with a non-refrigerated element are flushed and sanitized.The flush cycle preferably is repeated about every two (2) hours or so.

Sanitation is further improved by the milk hoses 140, 150 and themixture hose 220 being disposable. As such, the hoses 140, 150, 220 maybe replaced daily. Likewise, the hose connector 185 and the nozzleinsert 300 of the nozzle body 240 may be removed and sanitized each day.Further, the connectors used herein may be barbed to prevent crevicebuild up. The milk system 100 thus provides for quick and easy cleaningand sanitation.

Alternatively, the foamed milk system 100 also may include a cleaningblock junction 390 depicted in FIG. 4. The cleaning block junction 390may replace the hose connector 185. The cleaning block junction 390 maycontain four (4) hose fittings 400, 410, 420, 430. The first three (3)fittings 400, 410, 420 may be connected to the milk hose 150, the airhose 180, and the mixture hose 220 in the manner described above withrespect to the hose connector 185. The fourth fitting 430 may beconnected to a flush water hose (not shown). Hot water may be forcedthrough the flush water hose and into the cleaning block junction 390 tosterilize the foamed milk system 100. The hot water may travel throughthe mixture hose 220, the mixture inlet 230, the mixing area 310, theexpansion area 340, and the diffuser 350 to sterilize the foamed milksystem 100 as is described above. The system 100 as a whole may then bereoriented to producing the steamed milk and foam as is described above.

It should be apparent that the foregoing relates only to the preferredembodiments of the present invention and that numerous changes andmodifications may be made herein without departing from the spirit andscope of the invention as defined by the following claims andequivalents thereof.

1. A foamed milk system for creating foamed milk from a source of milk,a source of air, and a source of steam, comprising: a milk inlet systemfor pressurizing the milk; an air inlet system for pressurizing the air;a mixing area to mix the pressurized milk, the pressurized air, and thesteam; the mixing area comprising an annular region formed between aninner wall of a hollow nozzle block and a mixture nozzle positionedwithin the hollow nozzle block; and an expansion area to expand themixture of the pressurized milk, the pressurized air, and the steam. 2.The foamed milk system of claim 1, wherein said milk inlet systemcomprises a peristaltic pump.
 3. The foamed milk system of claim 2,wherein said milk inlet system comprises a disposable hose connectingthe source of milk and said peristaltic pump.
 4. The foamed milk systemof claim 1, wherein the air inlet system comprises an air pump.
 5. Thefoamed milk system of claim 1, further comprising a hose connectorconnecting said milk inlet system and said air inlet system.
 6. Thefoamed milk system of claim 5, wherein said hose connector comprises athree-way valve.
 7. The foamed milk system of claim 5, wherein said hoseconnector comprises a four-way valve.
 8. The foam milk system of claim5, wherein said hose connector comprises a plurality of barbedconnections.
 9. The foamed milk system of claim 5, wherein said milkinlet system comprises a disposable hose connecting said hose connector.10. The foamed milk system of claim 5, wherein said air inlet systemcomprises a disposable hose connecting said hose connector.
 11. Thefoamed milk system of claim 10, wherein said disposable hose comprises amicrofilter positioned therein.
 12. The foamed milk system of claim 10,wherein said disposable hose comprises one or more check valvespositioned therein.
 13. The foamed milk system of claim 5, furthercomprising a disposable hose connecting said hose connector and saidmixing area.
 14. The foamed milk system of claim 1, further comprising asteam hose connecting the source of steam and said mixing area.
 15. Thefoamed milk system of claim 1, wherein said mixture nozzle comprises aplurality of protrusions positioned thereon.
 16. The foamed milk systemof claim 15, wherein said mixture nozzle comprises a plurality oforifice areas positioned about said plurality of protrusions.
 17. Thefoamed milk system of claim 1, wherein said mixture nozzle comprises aremovable nozzle.
 18. The foamed milk system of claim 1, furthercomprising a diffuser to gather the flow of the foamed milk to bedispensed.
 19. The foamed milk system of claim 18, wherein said diffusercomprises a diffuser insert and a spout.
 20. The foamed milk system ofclaim 1, further comprising a sanitation system.
 21. The foamed milksystem of claim 20, wherein said sanitation system comprises a source ofhot water.
 22. The foamed milk system of claim 21, wherein saidsanitation system comprises a sanitation valve adjacent to said sourceof hot water so as to provide hot water to said mixing area and saidexpansion area.
 23. A steamed milk system for creating steamed milk frompressurized milk and steam, comprising: a mixing area to mix thepressurized milk and the steam; a pressurized milk inlet system forinjecting the pressurized milk into the said mixing area; a steam inletsystem for injecting the steam into said mixing area; said mixing areacomprising an annular region formed between an inner wall of a hollownozzle block and a mixture nozzle positioned within the hollow nozzleblock; an expansion area to expand the pressurized milk and the steam toform a flow of steamed milk; and a diffuser to gather the flow of thesteamed milk to be dispensed.